Rail speed control arrangement for textile machines



H. WOLF Aug. 20, 1968 RAIL SPEED CONTROL ARRANGEMENT FOR TEXTILE MACHINES 4 Sheets-Sheet 1 Filed Nov. 4, 1966 Fig. 1

Aug. 20, 1968 H. WOLF 3,397,529

RAIL SPEED CONTROL ARRANGEMENT FOR TEXTILE MACHINES Filed Nov. 4, 1966 4 Sheets-Sheet 2' lnvenlor." Ha -sf Us if Aug. 20, 1968 H. WOLF 3,397,529

RAIL SPEED CONTROLARRANGEMENT FOR TEXTILE MACHINES Filed Nov. 4, 1966 4 Sheets-Sheet 3 Aug. 20, 1968 H. WOLF 3,397,529

RAIL SPEED CONTROL ARRANGEMENT FOR TEXTILE MACHINES 116d Nov 1966 4 Sheets-Sheet 4 Fig.4 Fi .3 55 "40 3a 36 55 56 40 as 36 Fig.5

United States Patent O 3,397,529 RAIL SPEED CONTROL ARRANGEMENT FOR TEXTILE MACHINES Horst Wolf, Albershausen, Wurttemberg, Germany, asslgnor to Zinser-Texfilmaschinen Gesellschaft mit beschraenkter Haftung, Ebersbach an der Fils, Germany Filed Nov. 4, 1966, Ser. No. 592,146 Claims priority, application Germany, Nov. 5, 1965, Z 11,846 21 Claims. (Cl. 57-98) ABSTRACT OF THE DISCLOSURE A rail speed control device for textile machines having sensing means for sensing the speed of traverse of the ra1l means and programming means for correlating the speed of the traverse with a pre-prograrnmed traverse speed. The comparison means controls the speed of the rail traverse by generating one signal if the speed is in excess of a pre-programmed speed and an opposite signal 1f sald speed is less than the pre-programmed speed.

The present invention relates to a rail speed control arrangement for a textile machine, and more particularly, to an arrangement for controlling the speed of a ring rail, spindle rail or winding rail of a textile machine, such as a draw twisting machine, spinning machine, twisting machine, fly frame machine, or winding machine.

Textile machines of this type have means for winding a thread yarn or roving onto cops or tubes while the respect1ve ran], for example a spindle rail or ring rail, eflFects the winding up of the yarn or roving in the form of a package on the respective cop or tube. For example, in a sp1nn1ng machine, the ring rail carries a row of spinning rmgs and in a twisting machine the rail carries a row of twisting rings along which travellers run which guide the yarn or roving. This type of rail also supports flyers 1n flyer spinning and flyer twisting machines, and yarn guides 1n winding machines.

The construction, operation, and purpose of rails of this type 1n textile machines is well known, and will not be further explained. The term rail is used in the present application in a broad sense, and is not limited to a rail of a particular shape and purpose, but generally indicates a support causing by its movement an axial displacement of a yarn or roving or other flexible elongated element, along a body, such as a cop, on which a yarn package is formed.

Known textile machines include drive means for reciprocating the rail continuously during the winding of a complete package.

Known drive means for reciprocating a rail have a control apparatus controlling the speed of the rail movement. Some constructions permit an adjustment of the speed of the rail during the winding of a package. However, it has been found that the known devices serving this purpose are incapable of controlling the rail speed with the required degree of accuracy.

It is one object of the invention to overcome this disadvantage of prior art constructions, and to provide a textile machine with a rail speed control arrangement accurately controlling the speed of the rail so that packages are precisely wound in such a manner that the finished package has desirable properties.

Another object of the invention is to control the rail of a textile machine to move during the formation of a package at a speed varying in accordance with a predetermined and selected program.

ICC

Another object of the invention is to compare the actual speed of movement of a rail in a textile machine with a predetermined selected speed, which may be constant or vary in accordance with a program.

Another object of the invention is to compare the actual speed of a rail in a textile machine with a selected speed, and adjust the speed of the rail until the compared speeds are equal.

Another object of the invention is to adjust the speed of the rail in accordance with a program represented by a record carrier.

Another object of the invention is to drive the rail by hydraulic drive means, and to adjust the speed of the rail by varying the amount of the fluid medium supplied to the hydraulic drive means.

With these objects in view, the present invention provides a control arrangement for controlling the speed of the rail of a textile machine, such as a draw twisting machine, spinning machine, twisting machine or fly frame rnachine.

One embodiment of the invention comprises a recipro cable rail means, for example a ring rail or spindle rail; drive means for reciprocating the rail means; control means connected with said drive means for adjusting the speed of reciprocation of the same, and preferably i cluding an adjustable valve in the supply of a fluid medium to hydraulic drive means; programing means which may be controlled by a record carrier or manually set to a constant or varying speed, and including first means for representing a selected desired speed of the rail means; feed back means operated by the rail means and including second means for representing the actual speed of the rail means; comparison means connected with the first and second means, and having third means controlled by the same to represent positive or negative differences between the actual speed of the rail means and the selected speed.

The third means are connected with the control means for actuating the same to adjust the speed of the rail means until the actual speed of the rail means is the same as the desired and selected speed.

The feed back means include means for measuring the effective speed of the rail means and controlling the second means for operating the same to represent the measured speed. The comparison means produces a differential control signal when the speed of the rail differs from the selected speed, and the magnitude of the dilferential control signal represents the difference between the selected speed and the rail speed, and is supplied to a motor of the control means operating adjustment means of the drive means of the rail means.

The differential control signal must contain an indication whether the rail speed is slower or faster than the selected speed so that the motor of the control means is driven in one direction, or in the opposite direction to obtain increase or decrease of the speed of the rail means by the operation of the adjusting means.

In the preferred embodiment of the invention, hydraulic piston and cylinder means are used for reciprocating the rail means. The adjusting means control a valve by which the amount of fluid medium, such as oil, supplied to the hydraulic piston and cylinder means, is adjusted. However, the drive means may also include an electric motor whose speed can be adjusted under the control of the differential control signal produced by the comparison means.

It has been found that the arrangement of the invention permits the maintaining of the speed of the rail exactly at a desired speed, and with greater accuracy than could be obtained by the apparatus of the prior art.

A particular advantage of the invention is that the speed of the rail means can be varied during'the winding of a yarn package at very high speed.

A record carrier, such as a program tape, may be used for controlling the first means to produce a signal representing a function according to which the selected speed varies during the winding of a package.

It has been found that a package wound by a textile machine incorporating the rail speed control arrangement of the present invention, has superior qualities as compared with packages produced by the machines of the priOr art. A particularly great improvement is obtained in draw twisting machines in which endless synthetic yarns are stretched and twisted.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a diagrammatic schematic view illustrating a first embodiment of an arrangement according to the invention;

FIG. la is a schematic diagram illustrating a first construction of measuring means, programing means, comparison means, and adjusting means which may be used in the embodiment of FIG. 1;

FIG. 1b is a schematic diagram illustrating a second construction of the measuring means, programing means, comparison means, and adjusting means which may be used in the embodiment of FIG. 1;

FIG. 10 is a schematic diagram illustrating a third construction of measuring means, comparison means, and adjusting means which may be used in the embodiment of FIG. 1;

FIG. 2 is a diagrammatic and schematic view illustrating a second embodiment of the arrangement of the invention;

FIGS. 3, 4, 5, and 6 are fragmentary schematic views illustrating different constructions for controlling the comparison device in the embodiment of FIG. 2;

FIGS. 7 and 8 are fragmentary schematic diagrams illustrating two diflFerent constructions of the adjusting control means by which the drive means of the rail is adjusted;

FIG. 9 is a diagrammatic schematic view illustrating a third embodiment of the arrangement of the invention; and

FIG. 10 is an elevation, partially in section, illustrating a reversing transmission which is advantageously used in the embodiment of FIG. 9.

Referring now to the drawing, in which like reference numerals indicate corresponding parts, the embodiments illustrated in FIGS. 1, 2 and 9 are shown to have hydraulic drive means operating ring rails in the embodiments of FIGS. 1 and 2, and a spindle rail in the embodiment of FIG. 9. While the hydraulic drive is preferred, other drive means may be used for the reciprocation of the rails.

In the embodiment of FIG. 1, the ring rail 1 carries rings 3 along which travellers move during the winding of packages a on cops so that bobbins 5 are made. The constructive details of such an apparatus are well known, and consequently not further described and illustrated.

Rail 1 has a bracket 14 with a slot in which a slide pin of an angular level 11 is located. Lever 11 is pivotable about a pivot pin, and has an arm ending in a slide located in a corresponding guide of a member 13 secured to the piston rod 8 of a piston 7a which is located in a hydraulic cylinder 7 and divides the same into two chambers respcctively communicating through conduits with ducts in the reversing valve 19 which is operated by an electromagnet 20 so that upon axial displacement of reversing valve 19 by electromagnet 20, the flow of a fluid medium to and from cylinder 7 is reversed. Valve 19 communicates with a pump 17 driven by motor 16 and connected with a tank 24 for a fluid medium, such as oil. The tank is connected by a volume control valve 22 to the ducts of reversing valve 19. In the illustrated position, oil will be pumped into the right end of hydraulic cylinder 7, and displaced from the left end into the tank through adjusting valve 22 so that the rail 1 will be moved downward by lever 11. When the direction of flow is reversed by operation of reversing valve 19, the piston will move in the opposite direction and lever 11 will raise rail 1. Adjusting valve 22 controls the amount of fluid medium flowing into and out of cylinder 7, and consequently the speed of reciprocation of rail 1. Instead of adjustable valve 22, adjustable throttles or diaphragms may be used, or a measuring and dispensing pump may be provided for adjusting the amount of fluid medium acting in the hydraulic motor 7, 7a, and it will be understood that the valve 22 is an adjusting means for adjusting drive means 7, 7a, 11 to vary the speed of reciprocation of rail 1. Adjusting means 22 is operated by an adjusting motor 34, motor 34 and adjusting means 22 together constituting control means for varying the speed of rail 1. Measuring means 12 are provided for measuring the actual effective speed of rail 1. Switches 28 and 29 are disposed spaced from each other in the vertical direction of reciprocation of rail 1, which carries an actuator member 26 for operating actuating arms 27 and 27 of switches 28, 29. The time between actuation of switches 28, 29 is a measure of the average speed of rail 1. The specific construction of switches 28, 29, and of actuator member 26 is not an object of the present invention, and the only requirement is that each switch is operated every time in exactly the same position of the rail. Furthermore, the switches are constructed so that actuator arms 27 and 27' respond only to upward movement of rail 1 with actuator member 26. Switches of this type are well known and available in the trade.

Switch 28 is connected with a timing means 30 of known construction, which starts running whenever switch 28 is actuated by member 26. The output of timing means 30 is connected by a line 2 to the first input of a comparison device 32 whose second input is connected by a line 2 with switch 29. The output 15 of the comparison device 32 is connected with adjusting motor 34.

The time of operation of timing means 30 is adjusted by program controlled means 70' which include sensing means for sensing recordings on a record carrier representing desired speed variations. Instead of program control means 70', a manual adjustment means 70 may be provided for setting the timing means 30.

As a further alternative, or addition, the distance between switches 28 and 29 may be adjusted. This may be accomplished by a nut means 6" carrying switch 29 and mounted on a threaded spindle 6', driven by a control motor 6 which is started, stopped, and reversed by pro gram control means 8 which may respond to a program on a tape representing desired speed variations.

Upon actuation of switch 28 by rail 1 and actuator member 26, the timing means is started and supplies after a manually or program selected time period, a signal to the comparison device. During this time, actuator member 26 moves toward switch 29, and when the same is actuated by actuator member 26, a signal is supplied to comparison device 32 through line 2. Depending on which signal arrives first, adjusting motor is turned in one or the other direction to operate the adjusting means 22 so that the speed of the drive means 7, 7a and of rail 1 is adjusted. If the signal from switch 29 arrives at the comparison device 32 before the signal of the timing means, which was set in accordance with a desired and selected speed, the rail moves too fast, and the speed of the drive means 7, 7a and of the rail 1 is reduced so that it takes a longer time for actuator member 26 to arrive at switch 29. When the selected time of operation of timing means 30 is the same as the time required for the movement of the rail between switches 28 and 29, no differential control signal is produced by the comparison device, and consequently no adjustment of the rail speed takes place, since the rail operates at a speed selected by setting the timing means either manually by device 70, or in accordance with a program by device 70'. When the timing means operate a constant time period, and the distance between switches 28, 29 is adjusted by program control means 8 and adjusting means 6, 6', 6", an impulse will be given to comparison device 32 by switch 29, such impulse being given the sooner the nearer switch 29 is placed to switch 28. If the impulse through line 2 arrives before or after the signal supplied by timing means 30 to comparison device 32, a diife'rential control signal is produced for adjusting by motor 34 the adjusting means 22 so that the speed of the rail is correspondingly adjusted until the impulse produced by switch 29 arrives at the same time as the impulse produced by the timing means 30, which was set to a constant time of operation representing a selected speed.

From the above description of FIG. 1, it will become apparent that the elements within the box 4 constitute programing means including first means 30 for representing a selected desired speed of the rail means, and that box 12 surrounds elements which constitute feed back means operated 'by rail 1 and including second means 28, 29 for representing the speed of the rail. Comparison means 32 is connected with the first means 30 and the second means 29, and has third means, not shown, which is controlled by signals received from the means 30 and the means 29 to produce a differential control signal which is applied to control means including control motor 34 and adjusting means 22 by which the drive means 7, 7a of rail 1 are adjusted to difierent speeds until the actual speed of the rail is the same as a selected speed determined by setting the timing means 30. The alternative program control means 8 with adjusting means 6, 6', 6" are also programming means including a first means 6", 30 for representing a selected desired speed of the rail.

FIG. 1a illustrates the circuit and arrangement of FIG. 1 in greater detail. The timing means 30 operates a switch 51' connected in series with a switch 52 in a line 50' which connects a source of voltage with control motor 34 by which adjusting means 22 is actuated. Motor 34 is connected by a contact 51 of switch 29 and another switch 52 in line 50 to the other terminal of the voltage source. Timing device 30 operates not only switch 51', but also switch 52, and switch 29 operates not only switch 51 but also switch 52', as indicated by broken lines. A line 53' connects switch 28 with timing device 30, and a line 53 connects switches 28 and 29 to each other.

Whenever switch 28 is actuated by rail 1 and actuating member 26, the switch contacts 51, 52, 51', 52' assome the positions illustrated in FIG. 1a. The timing device 30 is controlled by switch 28 through line 53' to open switch contact 51, and a relay forming part of switch 29 is energized by the closure of switch 28 to open switch contact 51. Timing device 30 starts running upon actuation of switch 28, and after a predetermined selected time period, switch contact 51' is closed, and switch contact 52 is opened. When switch 29 is actuated by actuator member 26, switch contact 51 closes and switch contact 52' opens.

When the circuit of line 50' is completed in this manner, control motor 34 is energized to rotate in one direction to adjust the speed of the rail by acting on adjusting means 22. If in the position of FIG. la, switch contact 51 is closed, line 50 connects control motor 34 to the source of voltage, and motor 34 rotates in the opposite direction for obtaining a corresponding adjustment of the speed of the rail so that the rail speed is lncreased when motor 34 runs in one direction, and is reduced when motor 34 runs in the opposite direction.

When switch 29 engaged by actuator member 26 closes switch contact 51 before switch contact 51 of the timing device is closed by the same, motor 34 rotates until switch contact 42 of timing device 30 is opened by the same after a predetermined time period.

Since switch contact 52' is opened when switch contact 51 closes, both circuits and 50 are opened so that the time, during which motor 34 was running, corresponds to the time difference between the later closing of switch contact 51 and the earlier closing of switch contact 51.

If switch contact 51' is closed first, the same operations take place, the dilference being that control motor 34 is connected to the voltage source in such a manner as to run in the opposite direction.

The adjustment of adjusting means 22 during one up and down movement of the rail 1 is proportionate to the time diiference between the moments of closure of switch contacts 51 and 51'. Consequently, the adjustment of adjusting means 22 is the smaller, the less the speed of rail ,1 dilfers from the desired and selected speed represented by setting of the timing means 30' either by manual operation to a constant speed, for example, or by program controlled means to a varying selected speed.

The construction of FIG. 1b may be substituted for the construction of FIG. 1a in the embodiment of FIG. 1.

A synchronous motor 30" constitutes the timing means, and is connected to switch 28 to be started when switch 28 is actuated by actuator member 26 on rail 1. A transmission schematically indicated at 31, connects synchronous timing motor 30" with the movable tap 33 of a potentiometer 35 which is connected by lines 39 and 39' to a device 46 which, together with potentiometer 35, constitutes the comparison means 32 of FIG. 1, as indicated by a box 32 in FIG. 1b. The box 4 indicates programming means which include a program controlled means 73 corresponding to element in 'FIG. 1, and a device 47 which produces a voltage representing a speed selected by program control means 73. The voltage signal of device 47 is supplied to device 46 and applied through lines 39, 39 to the ends of the potentiometer 35. When switch 29 is closed by actuator member 26, a signal is supplied through line 2 to device 46.

At the beginning of an operation, the tap 33 is placed in an end position. When rail 1 and actuator member 26 operate switch 28, timing motor 30" starts to run. When after a time period depending on the speed of rail 1, switch 29 is actuated, the voltage between line 39 and tap 33 is compared with the voltage supplied by device 47 representing a desired speed. The position of the tap 33, and the respective voltage supplied to device 46 represent the actual speed of the rail since tap 33 travels at a constant speed during the time period required for the rail and actuator member 26 to move from switch 28 to switch 29. A diiferential control signal is produced at the output of comparison device 46, and the magnitude and polarity of the diiferential control signal depends on the difference between the voltage produced by device 47 and represent ing a selected desired speed, and the voltage between tap 33 and line 39 representing the rail speed. The construc- .tion of the comparison device 46 which compares two voltage signals to produce a diiferential signal representing the difference of the voltages, and the polarity of the same, is well known and consequently, the inner circuit of the comparison device 46 will not be further explained.

Potentiometer 35 and voltage generator device 47 may be provided in the arms of a Wheatstone bridge so that the magnitude and polarity of the differential control signal is proportionate to the magnitude and polarity of the unbalanced bridge. In any event, the differential control signal produced by comparison device 46, is supplied to control motor 34 by which the adjusting means 22 are adjusted.

In some applications of the apparatus, it is sufficient to provide only switch 28, and to omit switch 29 as shown in FIG. 10. The timing means is connected by line 2 to the comparison means 32 which is also connected by a line 29' with switch 28 which is connected to the timing means 30 by a line 28.

After every second stroke of rail 1 in the direction of the arrow C, actuator member 26 actuates switch 28 to start the timing means 30. Intermediate to actuations of timing device 30 by switch 28, switch 28 is actuated to supply a signal through line 29 to comparison means 32. Timing means 30 is set to a selected time period representing a selected and desired average value of the effective speed of the rail during a complete up and down movement.

After the present time periods, a signal is supplied to comparison device 32, whereas the signal supplied through line 29 may arrive earlier or later depending on the speed of the rail and actuator member 26. Comparison device 32 responds to time differences between the signals supplied by timing means 30 and the signals applied by switch 28 to produce a ditferential control signal representing the speed difierence between the average speed of the rail, and the desired speed, and this control signal is supplied to control motor 34 for operating adjusting means accordingly to either increase or reduce the speed of rail 1, the direction of rotation of control motor 34 depending on the polarity of the differential control signal.

In the embodiment of FIG. 2, the rail 1 is reciprocated by drive means 7, 11, and the fluid medium is supplied through an adjusting valve means 22. to the reversing valve 19 which is controlled by an electromagnet 20, all as described with reference to FIG. 1. An adjusting motor 34 controls the adjusting means 22. A reversing transmission 34' is provided between the shaft of adjusting motor 34 and the adjusting means 22.

A programming means 18 by which a desired speed of the rail 1 is selected, include a program control means 70" controlling the speed of a motor 44 which drives a spindle 42 on which a nut 41 is mounted for axial movement. A reversing transmission 45 connects motor 44 with spindle 42, and reverses the direction of rotation of spindle 42 whenever an operating means 45' is actuated in a manner which will be explained hereinafter. By shifting reversing means 45, at time intervals, nut 41 is reciprocated along spindle 42 in the direction of the arrows B. The speed of motor 44 and the pitch of spindle 42 is selected so that nut 41 reciprocates at a selected speed which is desired for the reciprocation of rail 1. Rail 1 carries two actuator pins 36 between which the actuator arm of a comparison switch 32 is located, comparison switch 32 being secured to nut 41 for reciprocation with the same.

When rail 1 moves upward at a higher speed than nut 41 with comparison switch 32, 38, actuator pin 36 engages actuator arm 38, and a contact portion connected with arm 38 is moved into engagement with a switch contact 56, as best seen in FIG. 3. Contact 38 is connected by a line 56', contact 56 is connected by a line 56", and contact 55 is connected by a line 55 to control motor 34, lines 55', 56', and 56 being schematically illustrated by a line in FIG. 2.

At predetermined points of the path of movement of rail 1, operating means 45' is actuated to shift reversing means 45 so that comparison switch 32 is reciprocated at the desired and selected speed. Whenever the operating means 45' of reversing means 45 is actuated, a signal through a line 45 is supplied to the winding of electromagnet 20 so that reversing valve 19 reverses the hydraulic motor 7 so that rail 1 reciprocates with strokes which are equal to the strokes of comparison switch 32. In this manner, the reversal of the movement of the heavy rail 1 is accomplished without programing means 18, which is important for producing a precisely wound package of a bobbin 5.

When rail 1 reciprocates at the same speed as comparison switch 32, the contact of actuator arm 38 is in a position located between and spaced from contacts 55 and 56 shown in FIG. 3. When rail 1 moves too fast in upward direction, contact 38 assumes the position of FIG. 4, and control motor 34 rotates in one direction to operae adjustment means 22 to cause a reduction of the speed of drive means 7 and rail 1. If the speed of rail 1 is lower than the speed of comparison switch 32 in upward direction, arm 38 engages pin 36, and lines 56, 55' are connected by the contacts of actuator arm 38, so that control motor 34 rotates in the opposite direction and turns adjusting valve means 22 in the opposite direction for increasing the speed of rail 1 until rail 1 and pins 36 move at the same speed as nut 41, comparison switch 32, and actuator arm 38. Due to the construction of comparison switch 32, control motor 34 rotates in one direction when the rail moves upward, and in the opposite direction when the rail moves downward. This would cause turning of adjusting means 22 in opposite directions during the upward stroke and downward stroke of rail 1, and in order to prevent such improper operation, reversing transmission means 34 is located between control motor 34 and adjusting means 22, and is controlled by operating means 45 to reverse the direction of rotation of adjusting means 22 every time reversing means 45 is shifted at the ends of reciprocating strokes, and simultaneously with the reversal of the direction of rotation of control motor 34 at the ends of the strokes.

The comparison switch shown in FIG. 3 may be replaced by the comparison swifch shown in FIG. 4. As in FIG. 3, an actuator arm 38 is mounted for pivotal movement about a pivot 54, and has a contact connected to a line 56". The contacts of arm 38 is located between a pair of contacts 55 and 56, and two additional contacts 54 and 54" are located outside of contacts 55 and 54. The five lines connected to the contacts are also connected to control motor 34, and schematically indicated by line 40' in FIG. 2.

Control motor 34 is of the type which can operate at two different speeds. When one of contacts 55, 56 is engaged by contact 28, control motor 34 runs at a low speed either in one or the opposite direction. When the speed difference between the comparison switch 40 of FIG. 4 and the rail 1 is greater, arm 38 will be ang-ularly displaced a greater distance, and either contact 54 or contact 54" will be connected with line 56", resulting in rotation of the control motor 35 at the higher speed in one or the other direction of rotation. The comparison switch 32 may also be constructed as shown in FIGS. 5 and 6 in which actuator arm 38 turns a gear segment 58 meshing with a pinion 59 which is secured to the movable tap 60 of a potentiometer 65 which has two part circular resistors 65' and 66 connected by lines 68 and 69 to control motor 34, while another line 67 connects the movable tap 60 with motor 34. If arm 38 is displaced a small angular distance due to a small speed difference between rail 1 and comparison switch 32, motor 34 will be connected to a voltage source by great parts of re- Sistor 66 or 65' so that the motor will run slowly. As the speed dilference and the relative displacement between nut 41 and rail 1 increases, smaller portions of resistor 66 or 65 will reduce the voltage of control motor 34 so that the same will rotate faster in one or the opposite direction depending on which resistor 65, 66 is engaged by movable contact 60.

FIG. 6 illustrates another modification of comparison switch 32 in which a potentiometer having a single arcuate resistor 61 and a movable contact arm 60 is controlled by actuator arm 38. Lines 62 connect contacts 60 and the end of the resistor 61 with control motor 34. Each angular position of actuator arm 38 corresponds to a portion of resistor 61. Resistor 61 is connected into one arm of a Wheatstone bridge which is unbalanced to produce a voltage of a magnitude and polarity depending on the position of contact 60 on resistor 61. In this manner, control motor 34 can be caused to rotate in the required direction at a speed depending on the speed difference between the rail and the comparison switch 32.

In the embodiment of FIG. 2, the programing means 18 include first means 41 for representing a selected desired speed of the rail, and feed back means operated by the rail and including second means 36 for representing the actual speed of the rail. The comparison means 32 is connected with the first means 41 and with the second means 36, and has third means 55, 56, 56' controlled by the relative movements of the first means 41 and the second means 36 to represent positive and negative differences between the actual speed of the rail and the speed selected by program control means 70" at which motor 44 moves nut 41.

It is also often necessary to vary the speed of the rail during a stroke, or double stroke, which is accomplished by adjustment of adjusting means 22. According to the prior art, a speed changer means is used for this purpose, and as shown in FIG. 7, the speed changer means 72 operates a control device 77, which may be a motor for operating another volume controlling valve or adjusting means 75 which is connected in parallel with the adjusting valve 22 described with reference to FIGS. 1 and 2. A conduit in which valves 75 and 22 are connected in parallel, is connected to tank 24- and to reversing valve 19. Adjusting valve 22 is operated by control motor 34 which responds to the differential control signal produced by comparison device 32, as explained above.

While adjusting valve means 22 will be adjusted to increase or reduce the speed of the rail means to correspond to a selected speed, valve 75 will be adjusted under the control of speed changer means 72 to supply additional fluid medium to the drive means 7 so that the speed of rail 1 will be varied during each reciprocating stroke in a manner determined by the known speed changer means 72. The average speed of the rail 'will be maintained by adjusting means 22 to correspond to the desired and selected average speed represented by programing means.

FIG. 8 illustrates a modified arrangement serving the same purpose. The speed changer means 72 adjusts the speed of control motor 34, which is also adjusted by differential control signal supplied thereto by the comparison device 32, as explained above. The control signal of comparison device 32 and the control signal produced by the speed changer means 72, are combined to cause rotation of control motor 34 in such a manner that adjusting valve means 22 is operated to provide fluid medium to the drive means 7, 7a in amounts which depend not only on the average speed of the rail, but also on a desired speed change during each stroke of the rail.

In the embodiment of FIG. 9, the rail 1 is a spindle rai'l for moving spindles with bobbins in the directions of the arrows A. Only one spindle is illustrated at 90, and it will be understood that the long row of spindles 90 is provided on the reciprocating spindle rail 1, and that means are provided for winding a yarn or roving onto the spindles and cops thereon. The drive means 7, the reversing valve 19, and the adjusting valve 22, pump 17, motor 16, and tank 24- are the same as in the embodiment of FIGS. 1 and 2, and adjusting means 22 is operated by a control motor 34.

An actuating member 92 is secured to rail 1' and has a friction surface 91 extending in the direction of reciprocation of rail 1'. As shown in FIG. 10, friction surface 91 has two spaced portions provided on the legs of a C-shaped actuating member. Rollers 93 cooperate with friction surfaces 91, respectively, and as best seen in FIG. 10, annular friction members 93', 93" are secured to annular parts of overrunning clutches or one-way clutches 76' and 78' which are respectively mounted on a pair of shafts carrying bevel gears 78, 76 meshing with a bevel gear 99 on a shaft 97. The reversing transmission of FIG. is schematically indicated at 94 and 95 in FIG. 9, and it will be understood that during the upward stroke of actuating member 92 with rail 1, shaft 97 will be driven by roller means 93', 76' in one direction of rotation, and during the opposite stroke of actuating member 92 with rail 1 by roller means 93", 78 through bevel gear 78 in the same direction. The reversing means 95 reverses the opposite strokes of rail 1' so that shaft 97 rotates continuously in the same direction.

A tacho-generator 96 is driven by shaft 97 to produce a voltage representing the speed of rail 1, and the voltage signal is supplied to a comparison device 32' which receives a voltage signal representing a selected and desired speed through a line 98 from a programming means 4. The voltage signal produced by the programming means 4', and the voltage signal produced by generator means 96 of the feed back means 96, 95, 93, 92 are compared by comparison means 32' which produces a differential control signal which is supplied through an amplifier 99 to control motor 34 which operates adjusting means 22 as explained above. Programming means 4' may be set to a constant voltage corresponding to a constant selected average speed of rail 1', or may be constructed as described with reference to FIG. 1b in which a voltage generator 47 produces a varying voltage representing desired speed variations under the control of a program controlled means which may respond to a program provided on a record carrier.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of speed control arrangements for textile machines differing from the types described above.

While the invention has been illustrated and described as embodied in an arrangement for controlling the speed of a spindle rail, ring rail, or other rail serving a similar purpose so that the rail operates at a desired and selected speed which is preferably controlled in accordance with a program, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. Rail speed control arrangement for a textile machine, comprising, in combination, reciprocable rail means; drive means for reciprocating said rail means; control means connected with said drive means for adjusting the speed of reciprocation of said rail means; programming means including first means for representing a selected desired speed of said rail means; feed back means operated by said rail means and including second means for representing the actual speed of said rail means; comparison means connected with said first means and said second means, and having third means controlled by said first and second means to represent positive and negative difierences between said actual speed of said rail means and said selected speed, said third means being connected with said control means for actuating the same to adjust the speed of said rail means until the actual speed of said rail means is the same as said selected and desired speed.

2. An arrangement as defined in claim 1, wherein said third means of said comparison means produces a differential control signal when the speeds of said first and second means differ, said differential control signal representing the difference between said last mentioned speeds and being supplied to said control means so that the same effect an adjustment of the speed of said rail means proportionate to said signal.

3. An arrangement as defined in claim 2, wherein said first means produce a first signal proportionate to said selected speed, and said second means produce a second signal proportionate to the speed of said rail means; and wherein said comparison means combines said first'and second signals so that said third means produces said differential control signal.

4. An arrangement as defined in claim 1, wherein said first means of said programming means represents a constant selected speed.

5. An arrangement as defined in claim 1, wherein said programming means include program control means responsive to a program carrier and controlling said first means to represent a speed varying in accordance with a selected program so that the speed of said rail means varies in accordance with said selected program.

6. An arrangement as defined in claim 1, wherein said third means of said comparison means produces a differential control signal when the speeds of said first and second means differ, said differential control signal representing the difference between said last mentioned speeds and being supplied to said control means so that the same effect an adjustment of the speed of said rail proportionate to said signal; wherein said programming means include program control means respon ve to a program carrier and controlling said first'means to represent a speed varying in accordance with a selected program so that the speed of said rail means varies in accordance with said selected program; and wherein said third means produces a differential control signal of a magnitude proportionate to the difference between the momentary speed of said rail means and the program selected speed at the same moment.

7. An arrangement as defined in claim 1, wherein said feed back means include measuring means for measuring the effective speed of said rail means.

8. An arrangement as defined in claim 7 wherein said measuring means is actuated during reciprocation of said rail means in predetermined positions of the same so that the time between two actuations of said measuring means represents the average speed of said rail means between said positions; and wherein said first means of said programming means represent the selected and desired average speed of said rail mans.

9. An arrangement according to claim 8 wherein said predetermined positions of said rail means are spaced from each other in the direction of reciprocation of said rail means a predetermined distance.

10. An arrangement according to claim 7 wherein said predetermined positions of said rail means are the same position assumed by said rail means after two successive reciprocating strokes in one direction.

11. An arrangement according to claim 7 wherein said measuring means include two switches spaced from each other in the direction of reciprocation of said rail means, and respectively engaged and operated by said rail means in said predetermined positions.

12. An arrangement according to claim 11 wherein said programming means include means for varying the distance between said switches.

13. An arrangement according to claim 11 wherein said programming means include program control means for varying the distance between said switches in accordance with a program.

14. An arrangement as defined in claim 1 wherein said first means of said programming means includes a timing device having a timer switch connected with said comparison device for supplying a first signal to the same after a time period corresponding to the selected and desired speed; wherein said feedback means include switch means operated by said rail means for starting said timing means; wherein said second means produces a second signal representing the actual speed of said rail means under the control of the same, and supplies said second signal to said comparison means; and wherein said third means of said comparison means produces a differential control signal of said first and second signals when the speeds of said rail means is different from said selected speed.

15. An arrangement according to claim 14 wherein said second means includes a switch means arranged spaced from said first mentioned switch means in the direction of reciprocation of said rail means and being operated by said rail means to supply said second signal to said comparison device when actuated by said rail means so that the arrival of said second signal before or after said first signal indicates that the speed of said rail means is higher or lower than said selected speed.

16. An arrangement according to claim 13 wherein said comparison means includes a comparison device for comparing voltage signals, and for forming a differential voltage signal, and a potentiometer having a tap moved by said timing means so that the position of said tap at the end of the operation of said timing means represents the speed of said rail means, said tap and the terminals of said potentiometer being connected with said comparison device for supplying to the same a voltage signal representing the speed of said rail mans; and wherein said first means of said programming means produce a voltage signal representing a selected and desired speed and supplies said voltage signal to said comparison device so that the same forms a differential control signal supplied by said third means to said control means.

17. An arrangement according to claim 1 wherein said programming means includes a member reciprocating at a selected speed; wherein said comparison means is mounted on said member for reciprocation therewith and has an actuator operating said third means; and wherein said second means of said feedback means are coupled with said actuator and reciprocate in synchronism with said rail means so that said third means of said comparison means produces a control signal when the speed of said rail means is different from the speed of said reciprocating member and comparison means; and comprising means for reversing the reciprocating movement of said reciproeating member simultaneously with the reversal of the reciprocating motion of said rail means.

18. An arrangement according to claim 1 wherein said second means of said feedback means includes a tacho generator controlled by said rail means to produce a voltage signal representing the speed of said rail means, said voltage signal being supplied to said comparison means; wherein said first means of said programming means produces a voltage signal representing a selected and desired speed, and supplies said voltage signal to said comparison means; and wherein said third means of said comparison means produces a differential control signal of said first mentioned voltage signals and supplies the same to said control means.

19. An arrangement according to claim 18 and comprising a reversing transmission between said tacho voltage generator and said rail means for transforming the reciprocating motion of said rail means into a continuous rotation of said tacho voltage generator at a rotary speed proportionate to the average speed of reciprocation of said rail means.

20. An arrangement according to claim 19 wherein said reversing transmission includes a bar having a surface secured to said rail means for reciprocation therewith, a pair of rollers rolling on said bar, a pair of coaxial bevel gears, a pair of one-way clutches operating in opposite directions of said rotation and connecting said coaxial bevel gears respectively with said rollers, and an output bevel gear meshing with said coaxial bevel gears and connected to said tacho voltage generator for operating the same.

21. An arrangement according to claim 1 wherein said control means include a reversible motor and adjusting means operated by said control motor and adjusting the speed of said drive means and thereby the speed of reciprocation of said rail means; wherein said programming means include timing means producing a first signal after a selected time period proportionate to a desired speed of said rail means, and means for varying the length of said time period; wherein said second means of said feedback means include switch means for starting said timing means and for producing a second signal to said comparison means after a time period proportionate to the speed of movement of said rail means; and wherein said third means of said comparison means produces a differential control signal representing the positive or negative time dilference between said signals.

References Cited UNITED STATES PATENTS Kreamer 57-94 XR Granberry 57-98 Miller 242-263 Long 57-98 Pfiefer 57-98 XR Schippers et al. 242-263 XR Pfiefer 57-98 Mason et al. 57-98 FRANK I COHEN, Primary Examiner. DONALD E. WATKINS, Assistant Examiner. 

